As more electronic devices become interconnected and users consume more data, the demand on server system performance continues to increase. More and more data is being stored in internet “clouds” remote from devices that use the data. Clouds are implemented using servers arranged in server clusters (sometimes referred to as server farms). The increased demand for performance and capacity has led server system designers to look for ways to increase data rates and increase the server interconnect distance in switching architectures while keeping power consumption and system cost manageable.
Within server systems and within high performance computing architectures there can be multiple levels of interconnect between electronic devices. These levels can include within blade interconnect, within rack interconnect, rack-to-rack interconnect and rack-to-switch interconnect. Shorter interconnect (e.g., within rack and some rack-to-rack) is traditionally implemented with electrical cables (e.g., Ethernet cables, co-axial cables, twin-axial cables, etc.) depending on the required data rate. For longer distances, optical cables are sometimes used because fiber optic solutions offer high bandwidth for longer interconnect distances.
However, as high performance architectures emerge (e.g., 100 Gigabit Ethernet), traditional electrical approaches to device interconnections that support the required data rates are becoming increasingly expensive and power hungry. For example, to extend the reach of an electrical cable or extend the bandwidth of an electrical cable, higher quality cables may need to be developed, or advanced techniques of one or more of equalization, modulation, and data correction may be employed which increases power of the system and adds latency to the communication link. For some desired data rates and interconnect distances, there is presently not a viable solution. Optical transmission over optical fiber offers a solution, but at a severe penalty in power and cost. The present inventors have recognized a need for improvements in the interconnection between electronic devices.